Field
Aspects of the present invention generally relate to a communication device to be connected to an external device.
Description of the Related Art
In recent years, size and weight of digital cameras have been reduced, and a camera that can be attached to a human body has been known. Such a camera is called a wearable camera. An important characteristic of the wearable camera is hands-free operability by which a user can capture an image without using his/her hands. For example, a user wears an eyeglass-type wearable camera on an area near his/her eyes, and simply looks at an object. This enables an image of the object to be captured, unlike a conventional digital camera that a user needs to hold with the user's hands.
Digital cameras have recently started to include wireless communication functions. In addition, an application causing a digital camera to cooperate with another digital camera has been proposed. For example, the configuration in which a captured image is transmitted and received between digital cameras using a wireless local area network (LAN) communication function has been proposed.
However, in a case where cooperation of a web camera and a digital camera using a wireless communication function is taken into consideration, the following points are not fully considered in Japanese Patent Application Laid-Open No. 2010-283791. First, the hands-free operability, which is an intrinsic characteristic of the wearable camera, should not be degraded in an operation for connection. Secondly, since the wearable camera and the digital camera are battery driven devices, a wireless LAN should be disconnected to achieve energy saving when the communication is not needed. The wearable camera is particularly designed on the premise that a user wears it. For this reason, the wearable camera needs to be smaller and lighter than a digital camera and other mobile devices such as a mobile phone. Consequently, size and capacity of the battery of the wearable camera are limited, and a sufficient amount of drive time needs to be obtained with due consideration of such limitations.